1. Field of the Invention
The invention relates generally to engine hour meters and more particularly to a cordless machine operation detector using a vibration sensor.
2. Description of the Prior art
Engine hour meters are common in industrial equipment for monitoring engine hours. The owner of the equipment or the owner""s representative reads engine hours directly from the meter for triggering scheduled maintenance and/or determining equipment rental charges. In some cases the direct approach works well enough. However, there are several limitations of this approach.
A limitation of the direct approach is that the owner or representative must be present wherever the equipment is in use in order to view the engine hour meter and make a decision on the maintenance. Attempts have been made to resolve this limitation by integrating the engine hour meter with a radio system for transmitting the engine hours to a monitor station. Several manufacturers have designed this capability into their new equipment. However, in order to integrate this capability into existing equipment the wiring of the equipment must be retrofitted in a manner that is specialized for each type of equipment. Such specialized retrofits are often costly and time consuming.
Another limitation of the direct approach for rental equipment is that there is a tendency for the renters to steal hours by disconnecting the hour meter. Various tamper detection systems have been developed in order to resolve this limitation. However, while such systems may inform an owner that tampering has taken place, they do not inform the owner of the number of hours that were missed. Some tamper detection systems apply a lock to prevent the equipment from being used after tampering is detected. However, such systems suffer from the inconvenience of unlocking the equipment after false detections or inadvertent tampering. Moreover, unless the tamper detection systems are manufactured into the equipment as new, they may require a specialized retrofit for the equipment.
There is a need for an apparatus for communicating machine time to a monitor without integration of the apparatus into the machine.
It is therefore an object of the present invention to provide a cordless machine operation detector that requires no integration with the machine for detecting when the machine is operating.
Briefly, in a preferred embodiment, a machine operation detector of the present invention includes a vibration sensor, a location detector, a data logger, and a transceiver. The machine operation detector mounts to a machine. The vibration sensor detects when the machine is operating by sensing the vibrations that are caused by the machine during operation and provides a machine vibration operation indication. The location detector provides a geographical location and includes a time clock for providing time. The data logger uses time from the time clock and the operation indication from the vibration sensor for logging times of operation of the machine. The data logger also logs geographical locations associated with the machine operation. The transceiver communicates the times and locations of the operation of the machine through an interchange to a tracking monitor. The machine operation detector, the interchange, or the tracking monitor includes an engine time monitor and an alarm sensor. The engine time monitor tracks an accumulated time for the machine vibration operation indication. The alarm sensor provides alarms when pre-defined boundaries of engine time, location, or accumulated time are exceeded. The machine operation detector includes an internal battery. In a first embodiment, the machine operation detector uses the internal battery for cordless operation. In a second embodiment, the detector is connected to switched machine electrical power through the on-off switch for operating the machine. In this case the internal battery enables the alarm sensor to provide an alarm when the external power is off while the vibration sensor indicates that the machine is operating. Operation time of the machine could also be tracked by connecting the device to switched power from the machine key switch.
An advantage of the present invention is that the time and the location of a machine are provided without a requirement for interconnection with electrical wires of the machine.
These and other objects and advantages of the present invention will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiments which are illustrated in the various figures.